Where do you expect cells to concentrate when using a centrifuge?

When centrifuging a sample, cells are expected to concentrate at the bottom of the tube, forming a pellet. This occurs because the centrifuge exerts a gravitational force that pulls heavier components, like cells, toward the bottom. The centrifugal force generated during the spin causes denser materials to sediment out of the solution and accumulate in a distinct pellet.

As the cells are denser than the surrounding liquid, they move downwards, while lighter fractions, such as cell culture media or supernatants, remain in the upper portion of the tube. This separation is crucial for various laboratory processes where purification and isolation of cellular components are necessary.

In contrast, the other options describe scenarios that don’t accurately reflect what happens during centrifugation. The liquid portion would remain above the pellet, without the concentration of cells occurring there. Even distribution throughout the liquid is not observed under centrifugal force, as cells will gather at the bottom rather than being evenly dispersed. Finally, while cells may press against the walls of the tube as they sediment, the primary accumulation occurs at the bottom, where the pellet forms.